As conventional bitrate control methods that are used in compressing and recording a video image in a digital video recorder, CBR (constant bitrate) and VBR (variable bitrate) are known. In CBR, a code amount (the number of bits) per time segment is controlled so as to be constant. In VBR, the code amount per time segment is variably controlled. Usage of VBR improves the image quality of a video image without unduly increasing storage space for storing the video data by allocating larger code amounts to pictures of rapidly varying portions in the video image and having large information amounts, and allocating smaller code amounts to pictures having small information amounts.